1. Field of the Invention
The present invention relates to a laser active material. More specifically, it relates to a laser active material capable of possessing an active lasing medium substance at a high concentration, with very little concentration quenching, and having a long fluorescent service life.
2. Description of the Related Art
In solid lasers, a transition metal or rare earth atoms are generally used as an active lasing medium and single crystals or glass materials as a matrix. The active medium materials are contained in a small amount as impurities in the matrix to form the emission materials. Various laser active materials formed by combining different kinds of ion and matrices have been proposed.
Glass lasers composed of Nd.sup.3+ ion solubilized into glass matrices are commercially available, and these glass lasers are advantageous, compared to those utilizing single crystals as a matrix, in that various shapes can be readily formed, large size materials can be readily obtained, and especially in the case of phosphate glasses, relatively a large amount of active media can be doped so that a large power and large energy can be appropriately and instantaneously generated. Nevertheless, many problems remain in connection with these glass lasers.
Silicate glass lasers have an excellent mechanical strength and thermal shock resistance, but also have an unpreferably large concentration quenching. Namely, although a high discharge power can be obtained when a large amount of an Nd ion is included, concentration quenching occurs to shorten the fluorescent life time due to the addition of a large amount of an Nd ion. Thus, in practice, a large amount of Nd.sub.2 O.sub.3 cannot be dopped.
Phosphate glasses can contain a larger amount of Nd.sub.2 O.sub.3, compared to silicate glasses, but the concentration quenching is still large and thus in practice a large amount of Nd.sub.2 O.sub.3 cannot be included therein. Further, when a large amount of P.sub.2 O.sub.5 is included in the laser emission materials, the water-vapor resistance and thermal shock resistance are remarkably decreased, and this is also a very serious problems in the art.